I. Field
The following description relates generally to wireless communications, and more particularly to uplink (UL) grants for multiple carriers.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power, . . . ). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations.
Wireless communication systems oftentimes employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to a mobile device. A mobile device within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, a mobile device can transmit data to the base station or another mobile device.
Area tracking within a wireless communication system enables a tracking area location for user equipment (e.g., mobile device, mobile communication apparatus, cellular device, smartphone, etc.) to be defined. Typically, a network can request or page the user equipment (UE) in which the UE can respond with such tracking area location. This enables the tracking area location of the UE to be communicated and updated to the network.
Multi-carrier systems often employ cross-carrier operations which provide good system performance. In a multiple carrier system or environment, a user equipment can leverage multiple carriers (e.g., a carrier can include an amount of resources or a collection of resources, an amount of bandwidth, etc.). Within multi-carrier operation, an anchor carrier can be utilized to communicate information related to two or more carriers. Moreover, control information being absent can prevent data transmissions on these carriers. In other words, multi-carrier systems cannot distinguish for which carrier received control is applicable. In addition, within a multiple carrier system or environment, uplink (UL) and downlink (DL) control assignments can be costly in overhead and user equipment (UE) assignment monitoring for each carrier.